Certain prior art efforts have seen the use of circular grinding elements in order to effectuate the sharpening of the surfaces of particular mechanical tools. For example, the patent to Rochet, U.S. Pat. No. 3,626,645, illustrates the use of a cup-shaped grinding wheel in order to sharpen the edges of a twist drill. Thus, Rochet, like much of the prior art in the area, pertains solely to techniques for the sharpening of drills and drill bits.
In like regard, the patent to Lundin, U.S. Pat. No. 3,201,903, discloses a method of sharpening rock drill bits in which one face of the drill is ground while the grinding element overlaps a second face of the drill. Said patent further involves the use of electrolytic grinding concepts and, as such, represents a sophisticated, but yet complicated and somewhat expensive, approach to the problem of reconstituting dulled cutting edges.
Further shown in the prior art is a method of truing teeth of machinery utilized in order to form the teeth of the gears of certain types of machinery. The surfaces of said teeth comprise flat surfaces. Accordingly, said patent does not touch upon the more difficult problem of the sharpening of raking surfaces which are essentially concave in nature.
Another prior art effort relating to the general area appears in the patent to Wildhaber, U.S. Pat. No. 2,332,420, in which a cylindrical grinding element is utilized in order to sharpen essentially flat raking surfaces.
Thus, to the best knowledge of the Inventor, the prior art has not shown any practical means or method by which a concave raking surface of a circular saw may be readily formed or reconstituted. Accordingly, this observation has given rise to the present inventive activity.